The rapid growth of mobile data is heavily stressing the mobile cellular network, especially the radio access network. The radio access capacity urgently needs to be enhanced to meet the ever-increasing demanding. Meanwhile, the WLAN (wireless local network) market gradually grows. And, the convergence of a WLAN and a cellular network becomes an effective way to increase the radio access capacity.
One of the cellular-WLAN convergence solutions is to integrate a WLAN AP (access point) and a mobile cellular base station into a combo box (called as converged access node), so that the UE with dual-mode access capability may access the combo box via two radio interfaces. And the data traffic can be simultaneously transmitted via the two radio interfaces. The co-located WLAN AP and the base station have a common backhaul link connected to the mobile core network, and provide more capacity to the coverage area.
However, in such a multi-radio access environment with converged radio access, how to set up and manage radio bearers over a WLAN, e.g. a Wi-Fi radio interface, to conceal the connectionless-oriented Wi-Fi radio link in the lower layer, and enable the common IP and other upper layer applications for both radio interfaces, is still a critical problem to be solved.